Valve



Dec. 4, 1934.

R. E. NEWELL El AL VALVE Filed April 22, 1955 Patented Dec. 4, 1934PATENT v VALVE Robert E. Newell, Irwin, and John A. Robertshaw,

Greensburg, Pa., assignors to Robertshaw 'llhermostat Company,Youngwood, Pa., a corporation of Pennsylvania Application April 22,1933, Serial No. 667,488

12 Claims.

The present invention relates broadly to the art of fluid control, andmore particularly to an improved valve construction for effectingcontrol of fluid flow.

It is customary in the art to which our invention relates to efiect suchcontrol by means of thermostatic or pressure operated valves. Suchvalves as heretofore used have generally been of two types. For purposesof convenience, these types may be referred to as the throttling typeand the so-called snap-action type, theidifierences between which arewell recognized; Both types of valves possess certain desirablecharacteristics but these desirable characteristics are peculiar to thetypes, and neither of the two types possess the desirablecharacteristics of the other.

1 It has heretofore been proposed to combine the two types of valves inorder to provide a unitary structure possessing the desirablecharacteristics of both types of valves. In the copending application ofRobert E. Newell, Serial No. 471,723,

there is shown and described a construction wherein the advantages ofboth the throttling type and the snap-action type of valves may beobtained in a unitary structure. Such structure, however, includes botha snap-acting valve and a throttling valve, and isv relativelycomplicated, and the cost of manufacture thereof is relatively high.

-' By our invention we provide a control device or valve constructionwherein the advantages of both the throttling type valve and thesnap-action type valve may be obtainedin a single valve structurewithout utilizing two separate valves as heretofore proposed.

In accordance with our invention, we provide a control device or valveconstruction such that a fraction of its total capacity, which fractionmay be either'relatively large or small, may be opened or closed with asnap while the remainder of the valve capacity is made available or cutoff by a gradual or throttling action upon further changes in conditionswhich it is desired to control, such, for example, as further increasesor decreases in temperature beyond those at which the snap-actionoccurs.

In accordance with the preferred embodiment of our invention, we providea control device or valve mechanism wherein the snap action is obtainedby means of a flexible element which is of such character that it willnot be damaged by over-strains, and which, after the snap-action hasoccurred and the control means operated by a snap movement, willcontinue to operate the control means above the snap range with agraduated action without straining any of the valve mechanism. One oftheadvantages of such a structure is that it may be operated over agreater range of temperatures, jamming of the parts avoided, and theadvantages of both the throttling and snap-action valves obtained in aunitary structure. In accordance with the preferred embodiment of ourinvention, the flexible element is a concave spring steel tape. Aflexible element 5 of this character in effecting the snap-actionchanges from a concave strip to a flat strip. This is advantageous overthe usual concavo-convex type of flexible element, as it is of suchcharacacter to enable it to continue to bend after the 7 snap hasoccurred without undue straining of the metal.

Control devices of the above character may be advantageously'used in thecontrol of temperatures of either liquids or gases. Where thetemperature of a liquid is to be controlled and the thermostatic elementextends from the control device into the liquid whose temperature is tobe controlled, it is desirable to provide suitable sealing means toprevent the escape of the liquid 30 into the control device or valvemechanism. Consequently, by our invention we also provide novel sealingmeans for preventing leakage of the fluid directly into the gas passageto the burner.

In the accompanying drawing, we have shown for purposes of illustrationonly, a preferred embodiment of our invention.

In the drawing- Figure 1 is a sectional view through the struc- 90 turewhich we provide, the thermostatic element being partially shown'inelevation, and the parts being shown in normal or inoperative position;

Figure 2 is a sectional view similar to that shown in Figure 1 with theparts shown in an 5 operative position;

v Figure 3 is an elevational view of the flexible element and theconnecting link shown in Figures 1 and 2;

Figure 4 is an elevational'view of the flexible c element and connectinglink shown in Figure 3 taken at right angles to the showing of Figure 3;and

Figure 5 is a sectional view taken along the line V-V of Figure 3.

Referring to the drawing, there is illustrated a valve structurecomprising a suitable casing 2 having an inlet port 3 and 'an outletport 4 therein, the flow between which is controlled by the novelstructure which we provide by our in- 11 vention. A valve member 5 isprovided between the inlet and outlet ports and cooperates with a valveseat 6 threaded in the valve casing. The valve seat 6 has a plurality ofopenings '7 therethrough through which the fluid passes in its passagefrom the inlet opening to the outlet opening of the structure. One endof a spring 8 surrounds a boss 9 carried by the valve member and bearsat its opposite end against a cap 10 and yieldably urges the valvemember against its seat 6. The cap 10 is threaded into the easing 2 andmay be readily removed to permit access to the ports.

A valve. stem or pin 11' extends throughan opening 12 in the valve seat6 and is adapted to cooperate with the flexible element 13 for openingthe valve to permit fluid to flow between the inlet and the outletopenings. The stem or pin bears at its free end against the flexibleelement 13 when said element is in a flexed position and is spaced aslight distance from it when the parts are in the position shown inFigure 1.

As shown in the drawing, the flexible element through which both thesnap-action and the throttling action are imparted to the valvecomprises a short piece of concave spring steel tape. The upper end ofthe flexible element 13 is riveted or otherwise suitably secured to aconnecting lever 14 located in the outlet passage 4 of the valvestructure. The connecting lever 14 is provided adjacent the upper endthereof with a recess 15 adapted to cooperate with one end of a glandpin 16 adapted to be actuated by the thermostat indicated generally bythe reference character 17. The extreme upper end of the connectinglever 14 is provided with an opening 18 adapted to cooperate with andreceive a pin 19 carried by an adjusting screw 20 extending through athreaded opening in an extension 21 on the upper portion of the valvecasing 2. As shown in the drawing, the upper end of the connecting lever14 is bent inwardly adjacent the opening 18 to provide bearing surfaces22 adapted to bear against the rear face of the adjusting screw 20carrying the pivot pin 19.

The lower end of the flexible element 13 is provided with a concavesubstantially U-shaped reinforcing member 23 which is secured to thelower end of the flexible member by a rivet 24 having a bearing surface25 which cooperates with an adjusting screw and stop member 26 carriedby the valve casing. w

The valve casing is provided with an extension 32 adjacent the upper endthereof. The extension 32 has a threaded portion 33 which may bethreaded in a suitable opening 34 of a boiler-35, or any other structureto which it is to be 'attached.

The extension 32 is provided with an opening 36 into which the gland pin16 extends. This opening has an enlarged portion 37 which is threaded toreceive the threaded end of the expansible tube. 30 of the thermostat.The one end of the gland, pin 16 bears against the inner end of thenon-expansible rod 31 and any movement thereof is transmitted by the pin16 to the flexible element through the connections and parts describedhereinbefore.

Where the thermostat 17 extends into a liquid whose temperature is to becontrolled, it'is desirable to provide suitable means for preventing theliquid from leaking past the thermostat tubethreads and into the gasconduit of the valve structure. Accordingly, a sump 41 is provided inthe extension 32 for collecting any water that leaks past the threads,and suitable openings 42 are provided to discharge any water collectedin the sump. -'Ihe gland pin 16 is suitably ma chined to form a sealwith the passageway 36 'to prevent the escape of gas from the valvecasing into the sump 41.

The valve structure above described having been properly calibrated, andthe indicator with which such structures are generally provided set at-atemperature-of-130, for example, if the medium being controlled is at atemperature of 140, for example, the parts of the valve will be in theposition illustrated in Figure 1, wherein the valve member is effectivefor preventing fluid flow through the casing. When the medium cools to atemperature of 130", or slightly below, the rod 31 of the thermostatpushes the gland pin 16 inwardly and forces the lower portion of thelever 14 carrying the flexible element 13 inwardly until the bearingsurface 25 on the lower end of the flexible element engages the stop pin26. A further fall of 15 or 20, for example, will develop sufficientstrain on the flexible strip to cause it to snap and take the bentposition as shown in Figure 2, thereby moving the valve member 5 awayfrom its seat 6 by a snap action.

In the event of a further drop in the temperature of the medium beingcontrolled, the lever 14 will continue to flex the flexible element 13,causing the valve member 5 to further recede from its seat 6 with agradual movement. The valve member 5 may be gradually moved asubstantial distance without danger of straining or damaging the strip.Thus, there is secured in this one valve structure an operationcharacterized by an initial snap action followed by a subsequentthrottling or graduated action.

Upon reversal of temperatures, the release of pressure from the valvemember 5 through the stem 11 permits the spring 8 togradually force thevalve member back towards its seat. Thereafter, at a predeterminedtemperature, the snap action will occur and completely cut 011 thesupply of fluid being controlled, and the flexible element 11 willassume a non-flexed or inoperative position, such as shown in Figure 1of the drawing.

As can be readily seen, the structure which we provide can be much moreeconomically manufactured than a. structure utilizing two separatevalves, one a snap-acting valve and the other a slow-moving orthrottling valve, and that the structure which we provide can be usedwhere the temperatures being controlled vary over a wide range. Ordinaryconcavo-convex diaphragms, such as have been used in snap-action devicesheretofore, have a very limited movement. After snapping from a concaveposition, they instantly assume a convex position which limits theirfurther movement. In the event of wide variations of temperature, theysuffer permanent distortion by the resulting over-strains. As can bereadily seen, these conditions are clearly overcome in the structurewhich 'we provide.

While we have shown and described a preferred embodiment of ourinvention, it will be understood that we do not intend to be limitedthereby, but that the invention may be otherwise embodied within thescope of the appended claims.

We claim: Y

1. A control device comprising a trough 3 shaped flexible element, meansfor actuating said element, a stop member adjacent one end ofsaid'flexible element and adapted to limit the movement thereof, andcontrol means between said actuating means and said stop member cent oneend of said flexible element and adapted to limit the movement thereof,and control means between said actuating means and said stop memberadapted to be operated by the flexing of said element by the actuatingmeans.

3. A control device comprising a substantially trough-shaped flexibleelement adapted to move from a normal non-flexed position to a flexedposition with a snap-action, means for flexing said element, and controlmeans intermediate the ends of said element adapted to be operated bythe flexing thereof.

4. A control device comprising a flexible element adapted to move from anon-flexed position to a flexed position with a snap-action, ac-

tuating means operatively connected with said element adjacent one endthereof, stop means adjacent the other end of said element adapted tolimit the movement .thereof, and control means intermediate the ends ofsaid element adapted to be operated by the flexing thereof.

5. A control device comprising'asubstantially trough-shaped flexibleelement adapted to move from a non-flexed position to a flexed positionwith a snap-action, control means intermediate the ends of said elementadapted to be' operated by the flexing of said element, and means forflexing said element to impart the snap-action thereto and forthereafter effecting further flexing of said element. I

6. A control device comprising a flexible member adapted to move to aflexed position with a snap-action, control means intermediate the endsof said element adapted to be operated by the flexing of said element,and means for flexing said element to impart the snap-action thereto andfor thereafter effecting further flexing of said element, whereby asnap-action is imparted to the control means followed by a graduatedmovement.

7. A control device comprising a substantially trough-shaped flexibleelement adapted to move to a flexed position with a snap-action and toreturn to substantially normal position with a snap-action, actuatingmeans for flexing said element, control means intermediate the ends ofsaid element adapted to be operated by the flexing of said element, andmeans for returning said control means to normal position as saidflexible element returns to normal position.

8. A control device comprising a flexible element adapted to move from anormal position to a flexed position with a snap-action, control meansintermediate the ends of said element element cooperating with saidvalve member for gin) adapted to be operated by the flexing thereof,means for flexing said element to impart a snapaction thereto and forthereafter effecting further flexing of the element, and means forreturning said control means to normal position as said element returnsto normal position.

9. In a valve, a casing having an inlet and an outlet port, a valvemember in said casing between said inlet and outlet ports, a flexibleoperating the same, said flexible element being adapted to move from anormal position to a flexed position with a snap-action, and means forflexing the flexible element to impart a snapaction thereto and forthereafter effecting further flexing thereof, whereby a snap-action isimparted to said valve member followed by a further gradual movement.

10. In a valve, a casing having an inlet and an outlet port, a valvemember in said casing between said inlet and outlet ports, a flexibleelement cooperating with said valve member for operating the same, saidflexible element being adapted to move from a normal position to aflexed positionwith a snap-action, means for flexing the flexibleelement to'impart a snapaction thereto and for thereafter effectingfurther flexing thereof, whereby a snap-action is imparted to, saidvalve member followed by a further gradual movement, and means forreturning said valve member to normal position.

11. In a valve, a casing having an inlet and an outlet port, a valvemember in said casing between said inlet and outlet ports, a flexibleelement mounted in said casing and adapted 11 to operate said valvemember, said flexible ele-' ment being normally in a non-flexed positionand adapted to move from a non-flexed position to a flexed position witha snap-action, and means for actuating said flexible element to effect asnapaction thereof and for thereafter effecting a further gradualflexing thereof.

12. In a valve, a casing having an inlet and an outlet port, a valvemember in said casing between said inlet and outlet ports, a flexibleelement mounted in said casing and adapted to operate said valve member,said flexible element being normally in a nonflexed position and adaptedto move from a non-flexed position to a flexed position with asnap-action, and means for actuating said flexible element to effect asnap-action thereof and for thereafter effecting a further gradualvflexing thereof. whereby an initial snap-action and a subsequent slowgradual movement is imparted to said valve member.

ROBERT E. NEWELL. JOHN A. ROBERTSHAW.

